Resolution
If Media Resource Groups are used, ensure that the Music on Hold (MoH) server is part of the Media Resource Group and that the group belongs to a Media Resource List. Also check that your Cicso IP phone belongs to the Media Resource List. If, after verifying the MoH configuration as described in Music On Hold, and there is still no MoH delivered to Public Switched Telephone Network (PSTN) callers, then you may be encountering Cisco bug ID CSCdv43814.
As a workaround, check the Media Termination Point (MTP) required check box on the gateway configuration page, and reset the gateway. For further troubleshooting refer the document Tone on Hold is playing instead of Music on Hold.
